Buggy code:
public class FolderOptionsDialog extends JDialog implements ActionListener , ListSelectionListener { public static final String [ ] tooltips = new String [ ] { "columns" , "sorting" , "filter" , "threadedview" , "selection" } ; private JPanel generalPanel ; private JPanel advPanel ; private AbstractMessageFolder folder ; private JLabel nameLabel ; private JTextField nameTextField ; private JLabel totalLabel ; private JLabel totalLabel2 ; private JLabel unreadLabel ; private JLabel unreadLabel2 ; private JLabel recentLabel ; private JLabel recentLabel2 ; private JLabel locationLabel ; private JLabel locationLabel2 ; private JLabel sizeLabel ; private JLabel sizeLabel2 ; private JButton exportButton ; private MultiLineLabel enableLabel ; private JCheckBox enableTextIndexingCheckBox ; private boolean renameFolder ; private String oldFolderName = null ; private MultiLineLabel overwriteLabel ; private JButton resetButton ; private JButton enableButton ; private JButton disableButton ; private CheckableTooltipList checkableList ; private MailFrameMediator mediator ; public FolderOptionsDialog ( AbstractMessageFolder folder , boolean renameFolder , MailFrameMediator mediator ) { } public FolderOptionsDialog ( AbstractMessageFolder folder , MailFrameMediator mediator ) { } protected JPanel createGeneralPanel ( ) { } protected JPanel createAdvancedPanel ( ) { } protected void initComponents ( ) { } protected JPanel createButtonPanel ( ) { } public void updateComponents ( boolean b ) { if ( b ) { MailboxInfo info = folder . getMessageFolderInfo ( ) ; nameTextField . setText ( folder . getName ( ) ) ; totalLabel2 . setText ( Integer . toString ( info . getExists ( ) ) ) ; unreadLabel2 . setText ( Integer . toString ( info . getUnseen ( ) ) ) ; recentLabel2 . setText ( Integer . toString ( info . getRecent ( ) ) ) ; locationLabel2 . setText ( folder . getDirectoryFile ( ) . getPath ( ) ) ; IFolderItem item = folder . getConfiguration ( ) ; XmlElement property = item . getElement ( "property" ) ; CheckableItemListTableModel model = new CheckableItemListTableModel ( ) ; for ( int i = 0 ; i < ( property . count ( ) ) ; i ++ ) { OptionsItem optionsItem = new OptionsItem ( ( ( XmlElement ) ( property . getElement ( i ) . clone ( ) ) ) ) ; model . addElement ( optionsItem ) ; } checkableList . setModel ( model ) ; if ( ( folder ) instanceof AbstractLocalFolder ) { item = folder . getConfiguration ( ) ; boolean bool = item . getBoolean ( "property" , "enable_lucene" ) ; enableTextIndexingCheckBox . setSelected ( bool ) ; } else { enableTextIndexingCheckBox . setEnabled ( false ) ; } } else { if ( renameFolder ) { if ( ! ( oldFolderName . equals ( nameTextField . getText ( ) ) ) ) { MailFolderCommandReference r = new MailFolderCommandReference ( folder ) ; r . setFolderName ( nameTextField . getText ( ) ) ; CommandProcessor . getInstance ( ) . addOp ( new org . columba . mail . folder . command . RenameFolderCommand ( r ) ) ; } } IFolderItem item = folder . getConfiguration ( ) ; XmlElement property = item . getElement ( "property" ) ; property . removeAllElements ( ) ; CheckableItemListTableModel model = ( ( CheckableItemListTableModel ) ( checkableList . getModel ( ) ) ) ; for ( int i = 0 ; i < ( model . count ( ) ) ; i ++ ) { OptionsItem optionsItem = ( ( OptionsItem ) ( model . getElement ( i ) ) ) ; property . addElement ( optionsItem . getElement ( ) ) ; } if ( ( folder ) instanceof AbstractLocalFolder ) { item = folder . getConfiguration ( ) ; boolean bool = enableTextIndexingCheckBox . isSelected ( ) ; <START_BUG> item . set ( "property" , "enable_lucene" , bool ) ; <END_BUG> AbstractLocalFolder localFolder = ( ( AbstractLocalFolder ) ( folder ) ) ; DefaultSearchEngine engine = null ; if ( bool ) { localFolder . setSearchEngine ( null ) ; MailFolderCommandReference r = new MailFolderCommandReference ( folder ) ; CommandProcessor . getInstance ( ) . addOp ( new org . columba . mail . folder . command . SyncSearchEngineCommand ( r ) ) ; } else { localFolder . setSearchEngine ( null ) ; } } getMediator ( ) . getFolderOptionsController ( ) . load ( STATE_BEFORE ) ; MailFolderCommandReference r = new MailFolderCommandReference ( folder ) ; CommandProcessor . getInstance ( ) . addOp ( new org . columba . mail . gui . table . command . ViewHeaderListCommand ( getMediator ( ) , r ) ) ; } } public void actionPerformed ( ActionEvent arg0 ) { } private void updateButtonState ( boolean selected ) { } public void valueChanged ( ListSelectionEvent e ) { } public MailFrameMediator getMediator ( ) { } }

Fix:
item . setBoolean ( "property" , "enable_lucene" , bool ) ;